Existing laser transmitters for optical communication and ranging applications operate at wavelengths already occupied by the high background noise of the solar spectrum, making reception difficult. For undersea and sea surface penetrating applications, existing systems use dye lasers with material lifetime problems and expensive secondary optical pumping lasers, or xenon chloride excimer lasers with toxic, corrosive gases and 1300 degrees C. lead vapor Raman cells, or solid-state neodymium based lasers at wavelengths outside the peak seawater transmission band, or low peak power, 1500 degrees C. copper vapor lasers. The excimer/lead Raman system also requires wavelength control to milli-Angstrom tolerances and must even compensate for doppler shift due to relative platform motion to be detected by the associated atomic resonance receivers.
Thus, a need currently exists in the state of the art for an improvement in laser communication and ranging systems using a comparatively simple, solid-state high peak-power laser transmitter operating at a select wavelength of minimum solar background radiation and maximum blue-seawater transmission.